Machines such as industrial robots are provided with sensors for measuring force or torque that is applied during work.
Such a sensor may prevent a machine failure or a safety accident, and promptly recognizes an unexpected accident to enable a quick response.
A sensor configured to perform the above-described function includes, for example, a differential transformer sensor that uses the difference between magnetizations of a tense direction or compression direction when stress is applied to a ferromagnetic material, a phase difference detection sensor that detects a torsional angle caused by a torque load, and a sensor using a strain gauge.
The sensor using a strain gauge has a problem in that a relatively accurate strain measurement is enabled only when a point at which deformation such as a tension or compression has occurred due to force or torque is found and the strain gauge is attached to the correct point.
In this case, a solution that can improve inconvenience in measuring a strain and also enhance accuracy of the measurement value is needed